Bearing Failure RCA: Cage Damage

 

When a rolling bearing is damaged during machine operation, the entire machine or equipment can seize or malfunction. Since bearings that fail prematurely or unexpectedly cause trouble, it is important to be able to identify and predict failure beforehand, so that preventive measures can be adopted.

Damage Condition

Cage damage includes: Cage deformation, fracture and wear; Fracture of cage pillars; Deformation of side face; Wear of pocket surface; and Wear of guide surface.

Possible Causes

  • Poor mounting (Bearing misalignment)
  • Poor handling
  • Large moment load
  • Shock and large vibration
  • Excessive rotation speed, sudden acceleration and deceleration
  • Poor lubrication
  • Temperature rise

Countermeasures

  • Check the mounting method
  • Check the temperature, rotation and load conditions
  • Reduce the vibration
  • Select a different cage type
  • Select a different lubrication method and/or lubricant

 

Cage Damage 1

Part: Cage of a deep groove ball bearing
Symptom: Fracture of pressed-steel cage pocket

 

Cage Damage 2

Part: Cage of an angular contact ball bearing
Symptom: Pocket pillar Fractures of a cast iron machined cage
Cause: Abnormal load action on cage due to misaligned mounting between inner and outer rings

 

Cage Damage 3

Part: Cage of an angular contact ball bearing
Symptom: Fracture of machined high-tension brass cage

 

Cage Damage 4

Part: Cage of a tapered roller bearing
Symptom: Pillar Fractures of pressed-steel cage

 

Cage Damage 5

Part: Cage of an angular contact ball bearing
Symptom: Pressed-steel cage deformation
Cause: Shock load due to poor handling

 

Cage Damage 6

Part: Cage of a cylindrical roller bearing
Symptom: Deformation of the side face of machined high-tension brass cage
Cause: Large shock during mounting

 

Cage Damage 7

Part: Cage of a cylindrical roller bearing
Symptom: Deformation and Wear of machined high-tension brass cage

 

Cage Damage 8

Part: Cage of an angular contact ball bearing
Symptom: Stepped Wear on the outside surface and pocket surface of machined high-tension brass cage

 

Source: NSK